692 



SODA, BIBOKATE OF. 



SODA AND CHLORINE KESIDUES. 



SODA, BIBOKATE OF. A late report of Prof. 

 J. D. Whitney contains an account of the re- 

 gion in California yielding borax, both in crys- 

 talline form and in solution in the waters of a 

 lake and of springs. This region, said to show- 

 evidences of past volcanic action, is in the vi- 

 cinity of Clear Lake, about sixty-five miles 

 northwest of Suisun Bay, and thirty-six miles 

 from the Pacific. A small lake lies eastward 

 of Clear Lake, and near an arm of the latter ; 

 its waters vary in extent, and it is said some- 

 times to become quite dry. Dr. Veatch, in 

 September, 1863, found the water of this lake 

 to contain borax ; and some months later an 

 extensive bed of crystals of the same salt was 

 discovered at the bottom of the lake, to which 

 latter, accordingly, the name of Borax Lake 

 lias been given. 



Water taken from this lake, September, 18G3, 

 as analyzed by Mr. G. E. Moore, yielded, in the 

 gallon, 2401.56 grains of solid matters, of which 

 about one-half was common salt, one-fourth car- 

 bonate of soda, and the remainder chiefly bi- 

 borate of soda, the amount of this being 281.48 

 grains of the anhydrous equivalent to 5P5.08 

 grains of the crystallized salt. The deposit 

 of crystalline borax lies immediately beneath 

 the waters of the lake, and in one or several 

 layers, being intermixed with a blue mad : its 

 total thickness, which is variable, was in one 

 place found to be eighteen inches. The crys- 

 tals of borax vary in size from quite small to 

 from two to three inches across ; and where 

 the crystallization has been perfect, the salt is 

 so pure as, after mere washing, to constitute 

 an article superior to some of the so-culled re- 

 uned borax of commerce. It is believed that, 

 by use of movable coffer-dams, millions of 

 pounds of borax may be obtained with profit 

 from the deposit. Besides supplying the local 

 demand, some two hundred tons are said to 

 have been, in 1865, shipped to New York. In 

 the neighborhood of Clear Lake also, sulphur 

 has been found, and a spring, the waters of 

 which contain large proportions of borax and 

 of bicarbonate of ammonia, etc. The Borax 

 Lake would appear to be, or otherwise to have 

 been in the past, fed by some source of saline 

 matters which exploration has not yet reached. 



SODA AND CHLORINE RESIDUES, 

 UTILIZATION OF. No more than an outline, 

 and that scarcely complete, can here be given 

 of the series of processes, quite complicated, 

 and of reactions still more so, involved in even 

 the most expeditious and effectual methods yet 

 devised for rendering innocuous, and convert- 

 ing to use, the residues or otherwise waste 

 products from the chlorine and soda manufac- 

 tures. The residues are bulky, and contain 

 matters comparatively difficult of chemical 

 treatment ; while the necessity for their trans- 

 formation is such as indicated in the outset of 

 the article on SODA, etc. ; and, in default of 

 such re-working, the proprietors have usually 

 to pay heavy damages for the injurious effects 

 of the teachings from the heaps. Among those 



who have attempted to utilize the soda wastes 

 are Varrentrap, Kuhlmann, Townsend and 

 Walker, Kopp, Spencer, and Fabre ; but many 

 of the processes proposed appear to be useful 

 only on the small scale. The practical chemict 

 or manufacturer, interested in possessing more 

 complete details of the methods now to be con- 

 sidered, is referred to an abridgment of a me- 

 moir by M. E. Kopp, appearing in the Chem- 

 ical News, vol. xiii., p. 27, and on (1866), or to 

 the original in the Bulletin de la Soc. Chim., 

 1865, and also to an article by M. P. A. Fabre 

 in Le Technologiste, August, 1864. 



In chlorine and chloride of lime works, the 

 materials commonly used are chlorhydric acid 

 and the peroxide or other suitable compound of 

 manganese. The residual liquors may be car- 

 ried away in gutters to reservoirs of silicious 

 stone or wooden vats, set at intervals at lower 

 levels, so that the different solid matters con- 

 tained may be successively deposited within 

 these, the streams being finally received in 

 large stone reservoirs. The limpid, yellowish- 

 brown liquid reaching the last contains some 

 free chlorine, much free chlorhydric acid, and 

 in solution also perchloride of iron, mono- and 

 sesqui-chloride of manganese, and some chlo- 

 rides of barium, calcium, magnesium, and alu- 

 minium, with traces of chlorides of cobalt and 

 nickel. Kopp's treatment of these residues is 

 essentially by soda-waste, which he regards as 

 principally composed of sulphide of calcium, 

 and carbonate, with a less amount of hydrate, 

 of lime. The waste, gradually fed into tho 

 reservoirs, is acted on by chlorhydric acid, car- 

 bonic and sulphydric acid gases being set free, 

 but the latter being at once re-converted into 

 chlorhydric acid, with deposit of free sulphur. 

 The waste is added until the liquor becomes 

 colorless and sulphydric acid gas begins to es- 

 cape freely. Allowing about six hours for com- 

 pletion of the deposit of sulphur, the latter can 

 then be collected ; and the sulphur being 

 washed, and in some cases afterward exposed 

 in beds for some months to the air and rain, is 

 finally used in the manufacture of sulphuric 

 acid. 



The liquor from which removal of sulphur 

 has thus been effected, is then siphoned off into 

 a separate cistern ; it contains much free chlor- 

 hydric acid. This liquor is now, within an air- 

 tight chamber holding some 30,000 litres, again 

 gradually saturated with soda-waste, being at 

 the same time warmed with steam to about 

 30 C. ; carbonic and sulphydric acid gases 

 are once more evolved, but without decom- 

 position of the latter; and the gases being 

 made to traverse other portions of moist and 

 warm soda- waste, the carbonic acid and water- 

 vapor decompose sulphide of calcium, leaving 

 carbonate of lime, and producing more sul- 

 phydric acid. The total resulting volume of 

 gases is then conveyed into a gasometer set 

 to prevent its oxidation in drainings of soda- 

 waste. 



The sulphur of the sulphydric 9id gas is 



